Effects of Repetitive Head Impacts on a Concussion Assessment Battery

Abstract

Purpose: The purpose of this study was to determine the relationship between repetitive head impacts (RHI) and clinical concussion assessments across a season among collegiate football (FB) and women's soccer (WSOC) players.

Methods: Fifteen male FB and 23 WSOC players participated in this study. Participants were included if they were medically cleared for unrestricted athletic participation. Participants were tested in a university athletic training room on two occasions: preseason (PRE) and postseason (POST). The outcome measures consisted of tandem gait (TG), Standardized Assessment of Concussion, Balance Error Scoring System, King-Devick (KD), clinical reaction time, and Immediate Post-Concussion Assessment and Cognitive Testing. Repetitive head impact during the season was quantified using the Head Impact Telemetry System (Simbex, NH) for FB and the Smart Impact Monitor (SIM; Triax Technologies, Norwalk, CT) for WSOC. Independent variables included total number of impacts, average magnitude of peak linear acceleration, cumulative linear exposure, and number of impacts ≥98g.

Results: Results from direct-entry multiple regression analyses suggest significant associations between RHI and both visual memory (R = 0.670, F = 6.487, P = 0.002) and TG (R = 0.636, F = 3.841, P = 0.029) for WSOC and between RHI and KD (R = 0.756, F = 5.579, P = 0.013) for FB, whereby those with greater exposure performed worse. No other regression analyses within or across groups were significant.

Conclusions: These data suggest that RHI do not represent clinically meaningful changes on a multifaceted and multimodal concussion assessment battery. However, there may be subtle visual/vestibular impairments as observed by the associations between RHI and visual memory/TG among WSOC, RHI, and KD among FB.